Sales of free-range eggs are up 6.1 per cent and organic varieties are up nine per cent, said Kantar.

However, price pressure and Brexit-linked increases in feed costs were now pushing some smaller producers out of the industry, warned Robert Gooch, head of the British Free Range Egg Producers’ Association.

He told The Grocer magazine that farm gate prices were being “gradually eroded”, falling from 100p per dozen in 2015 to 82p per dozen this year.

Mr Gooch said: “There is a lot of competition for supermarket business and is is now feeding through to suppliers.

“Many smaller producers, some of which are sole traders, are leaving because of price pressure.”